Federal prosecutors delved into the nitty gritty of the distribution, design and freshness of Miller Lite beer cans Monday as they sought to authenticate the physical evidence being used against star pitcher Roger Clemens in his perjury trial in the District’s federal courthouse.

A crushed beer can has played something of a leading role in the trial: Clemens’s former strength coach and chief accuser, Brian McNamee, used one to store needles, cotton balls and gauze he said he used to inject the baseball legend.

McNamee, who testified for a sixth and final day Monday, has said he recovered the can from Clemens’s recycling bin after injecting him with performance-enhancing drugs at his Manhattan apartment in 2001.

Displaying a chart that showed the evolution of the blue-and-gold Miller Lite can since the 1970s, government lawyers used the testimony of a beer company manager to try to back up McNamee’s assertion by putting a date on the can.

MillerCoors manager Anthony Manuele testified about the “freshness code” on the can in question and determined that it was filled in July 2001 at a North Carolina brewery and would have hit retail shelves in August.

On cross-examination, Clemens’s lawyer Rusty Hardin tried to raise doubt about McNamee’s story and pointed out that the company’s distribution map meant that the strength coach could have purchased the can in his home town of Breezy Point, N.Y.

Manuele’s testimony showed the lengths prosecutors have gone to try to authenticate evidence against Clemens, who is charged with perjury, making false statements and obstruction of Congress for denying to a House panel in 2008 that he had ever used performance-enhancing drugs. Congress was following up on a 2007 report by former senator George Mitchell that named dozens of ballplayers, including Clemens.

Government lawyers have already called a U.S. Postal Service employee to try to establish the likely date of a shipping receipt from steroid supplier Kirk Radomski to McNamee at Clemens’s Houston home.

The trial, now in its sixth week, again featured testimony from McNamee, who said Monday that he had supplied several big league ballplayers with performance-enhancing drugs and shared that information with law enforcement officials.

McNamee’s testimony regarding other ballplayers and performance-enhancing drugs was intended to suggest that he was not out to get Clemens when he began confiding in federal agents in 2007.

Defense attorneys for Clemens had opposed allowing McNamee to testify about the other players because of concerns about “guilt by association.” But U.S. District Judge Reggie Walton ruled that the government could introduce the information as a way to bolster McNamee’s credibility.

Last week, McNamee endured aggressive questioning by Hardin, Clemens’s lead attorney. He was forced to acknowledge that his story about injecting the baseball legend had evolved over time and that he had lied to federal agents and, separately, to police in a Florida criminal investigation.

But McNamee has largely remained unapologetic about his changing story. McNamee said Monday that he was loyal to Clemens and had no incentive to damage his employer’s reputation. The strength coach agreed to cooperate with federal agents, he said, to try to avoid getting in trouble for distributing the banned substances.

He told authorities about his involvement with several players, including pitchers Mike Stanton and Andy Pettitte and infielder Chuck Knoblauch. Earlier in the trial, Pettitte gave conflicting testimony about his memory of a conversation with Clemens about human growth hormone.

Before leaving the stand, McNamee said he regretted helping Clemens with performance-enhancing drugs. McNamee said he had become unemployable, ruined his marriage and his relationship with his children.

“I shouldn’t have gotten involved. I should have just educated and left it at that. I shouldn’t have enabled,” he said.

Prosecutors and defense attorneys also questioned a neighbor of Jose Canseco, Clemens’s former teammate. Alexander Lowrey was 11 years old at the time he attended a 1998 pool party at Canseco’s home, where he had his picture taken with Clemens.

McNamee alleges that Clemens and Canseco talked about performance-enhancing drugs at the party, but defense lawyers suggested that Clemens was playing golf during the time that McNamee attended.

Lowrey was questioned in an attempt to establish whether Clemens and McNamee could have been at the party together. Under cross-examination, Lowrey conceded to Hardin that he was uncertain of the date of the party or the exact times that he was there, raising questions about the timing of the conversation McNamee claimed to have observed.

Ann covers legal affairs in the District and Maryland for the Washington Post. Ann previously covered state government and politics in California, New Hampshire and Maryland. She joined the Post in 2005.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.

To pause and restart automatic updates, click "Live" or "Paused". If paused, you'll be notified of the number of additional comments that have come in.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.

Spam

Offensive

Disagree

Off-Topic

Among the criteria for featured comments: likes by users, replies by users, previous history of valuable commenting, and selection by moderators.

Content from Allstate This content is paid for by an advertiser and published by WP BrandStudio. The Washington Post newsroom was not involved in the creation of this content. Learn more about WP BrandStudio.